Contents of the Summer 2014 Northants News
All about my Greehouse Roland Tebbenham
I looked at
my plants in the greenhouse this spring  and realised that things had to
change. There were too many plants, some quite tatty, many appearing tired and
not flowering much. Then there was another consideration; they had invaded our
house: the bathroom, two bedrooms, and the kitchen. Radical action was required.
I decided to have a ‘spring clean’ and remove 20-25% of my plants, either to
the compost heap, sales table, or for propagation according to their condition.
This included my cacti, succulents, orchids, bulbs, bromeliads and cycads. I
figured some readers might have the same problems so I decided to write this
piece to inspire you to inspect your plants critically and look after them as
well as you can. As I write this during May most of the sorting out is complete;
there is more repotting and outstanding propagation tasks on the agenda.
14x8ft (3.6x2.4m) Crittall greenhouse was erected in 1980 and does show its age.
I have replaced some glass, but presently it is weatherproof, bar a few slight
leaks and drips in heavy rain caused by moss growing close to the glazing bars.
It is fitted with Papronet internal shading, six automated roof vents and four
low-level automated louvre vents. To maintain air movement in summer two fans
run during daylight hours.
winter it is heated with a 3kW BioGreen open flame natural-gas heater and 1.5kW
electric fan heater as back-up. I aim to maintain 8C at bench level, though it
can be much colder at floor level so I fitted soil warming cables to reduce the
risk of frost damage to those plants growing under the staging. I might yet
install twin-skin polycarbonate in the roof vents and door to improve thermal
efficiency in winter.
run a ‘hot box’ (from Two Wests & Elliott) where my Asclepiads and
Monadeniums live all-year-round as well as operating as a ‘hospital’ for
newly grafted plants. (Yes Tina you can see some Alluaudiopsis
procera for you). I
also have a propagator for seed raising and establishment of cuttings. I grow
some thirty Gasteria plants under the staging in the shadiest north-west
corner and they seem happy there and flower well. I also grow most of my Aloe
species and miniature hybrids under the bench on the opposite sunny side; they
have additional under bench horticultural fluorescent lights switched on during
the day all-year-round. The waterproof fittings and special-spectrum tubes came
from Two Wests many years ago.
arrangement of under-bench lighting also enables me to keep some Euphorbias
under the bench as part of my efforts to multiply Viscum
minimum the hemi-parasite I acquired from Keith Grantham’s collection in 2001.
I have reserved a sunny under-bench corner for South African bulbs, mainly Haemanthus,
Scadoxus, and Eucomis as well as a few Hippeastrum and an old Clivia. I no longer grow a
broad range of Zephyranthes, Habranthus and Lachenalia bulbs: I decided to constrain the number of different growing and
watering regimes needed to keep such a broad spectrum of plants performing at
their best. While some bulbs can tolerate a degree of neglect, many need to
follow a quite specific rhythm of treatment to flower well and thrive for many
sunniest (south-west facing) sand bed is reserved for a few taller Cerei,
including a Pachycereus I grew from seed and an old 6ft (1.8m) Cleistocactus
strausii that bears
a few flowers every year. There is now competition for that space by the few
Agaves I grow. Time will tell which plants win! Above them on two sunny shelves
fitted to the end wall opposite the door are my Ariocarpus and Sarcocaulon
plants, both of which appreciate the high light-levels.
Epiphytes and Tillandsias hang from the roof.
reserve under-bench space at the north-east (door) end for propagated plants
before they are banished to the cold-frame ready for Branch sales. There is
space competition outside the greenhouse as I need cold-frame space for lilies
and Lampranthus pots that inhabit our patio during the summer.
the north-west side I have a conventional soil bed enriched with peat and coarse
bark for Cycads in pots I germinated twenty years ago. I do have to watch out
for ants as they like to build nests in the cycad pots. Above the soil bed there
are epiphytes including Tillandsia
usneoides and Rhipsalis plants in hanging pots. A large caudiciform Ipomaea
platensis produces metres of annual growth scrambling along
wires and smothered with pink flowers each lasting one day in the mid-summer to
might be aware that I do like mesembs ... a lot! I grow mostly Lithops
other plants of both stemless and low-shrub type genera. The one-hundred plus Lithops
occupy a long shelf on the south east side, with some aberrant colour forms and
a few cultivars sharing the western corner bench top with the other members of
favourites from amongst the stemless mesembs that reward me with flowers every
year are Conophytum
Both are easy to grow in gritty compost and modest watering.
In fact there are
some flowers out during most months of the year in this area owing to the
different growing seasons of particular mesemb genera. I do try to water
carefully and observe resting periods, but most plants in small pots appreciate
being sprayed when at rest to reduce very significant shrivelling. It seems to
work for me, though I expect others may disagree.
Left: The Lithops shelf and below are some aberrant colour forms.
all-year spraying treatment also works for Sarcocaulon (now Monsonia)
that live on the shelf above the mesembs; indeed if you allow them to dry out
completely and the roots to desiccate they seldom resume normal growth. In my
experience even the most strenuous attempts with rooting hormone powder, warmth
and wetness are doomed to disappointment. I consider that particular genus to be
a real wonder of nature: adapted to live in a hard desert and yet they have
quite large, beautiful, papery-petalled flowers.
ejected around 150 plants this spring and now have roughly 350 succulents, 250
cacti and some 50 others (mainly bulbs and cycads) in the greenhouse. Most of my
bromeliads live in the house, only the spikiest Dyckias and Dueterochonias plus
my festoons of Tillandsia
are in the greenhouse. The cacti occupy most of the south-east staging with a
few succulents at the southern end; they are a mix of Alluaudia,
and other caudiciforms like Pterodiscus.
do have some cacti I grew from seed or acquired during the 1960s. Two venerable
Mammillarias flower every year; I won the
M. scrippsiana in
a raffle at a CSSGB meeting at the RHS Hall in London during 1967. I grew many
plants from seed, but this year I have selected only the best to keep. I also
discovered many duplicates during my spring clean; some I retained as they
showed contrasting attributes of a particular species, others were discarded
because they were damaged, poor flowerers, having weak spination, or with no
grow some cristate plants and try to grow the normal forms of the species as
well. Some of our speakers have inspired me to focus on particular genera
following their presentations. For example I have a few Espostoa
plants grown from habitat collected seed by Graham Charles and I have looked
carefully at my Thelocactus
plants following Martin Doorbar’s presentation to us earlier this year.
interests have varied throughout the past fifty years and I expect they will
continue so to do. However a few particular favourites have sustained my
interest throughout the period: notably Lithops
(as already highlighted) and Neoporteria
plants now just outnumber the Neoporteria
plants, but they are both wonderful genera; slow growing, with very ornamental
body colour, nice spines and (collectively) they bear interesting flowers of
used to grow more Gymnocalycium
species than I have room for now, but I have some nice large old plants and a
few smaller favourites such as G.
megatae, G mihanovicii and
G. ragonesei. I
find them harder to grow well than many other cactus genera, though my bęte
noir is Echinocereus.
I cannot get on well with them so I have two left only, for now! I keep some
Echinopsis hybrids for their fleeting flowers and a few Rebutias.
have accumulated a modest collection of sixteen Turbinicarpus
that will never grow me out of house and home, though the presumed hybrid ‘X
Lophoturb’ dwarfs its true species cousins. Is it an allopolyploid or what? It
has not set seed so I presume it is not self-fertile. By contrast the species
flower sporadically throughout the spring and early summer.
canno t finish without mentioning the genus Astrophytum.
(left) They are rightfully described as easy to grow from seed and ideal beginners’
plants. Oh yeah; try keeping them unmarked for forty-plus years. It is true that
they are mostly quite forgiving and they do flower very well as I have said
before in this magazine, but Astrophytum
asterias is a
temperamental species. I freely admit here that I do not appreciate the Astrophytum/Digitostigma
‘thing’ or the newest grotesque monstrose and variegated forms from the Far
East. Maybe I will change my mind sometime in the future? I doubt it!
hope I have inspired you to really look hard at your plants, weed out the poor
performers and understand why they are poor. This should improve your collection
and remind you not to squeeze too many plants into a restricted space as I have
done over the past few years!
Roland and who would have thought that Mrs Dell would confuse megatae
(as in the Gymno) with megadeal?
has raised some interesting points here. What do we do when GH space is finite
and plants keep growing?